A Green Synthesis of CoFe₂O₄ Decorated ZIF-8 Composite for Electrochemical Oxygen Evolution

Abstract

Low-cost, sustainable hydrogen production requires noble metal-free electrocatalysts for water splitting. In this study, we prepared zeolitic imidazolate frameworks (ZIF) decorated with CoFe2O4 spinel nanoparticles as active catalysts for oxygen evolution reaction (OER). The CoFe2O4 nanoparticles were synthesized by converting agricultural bio-waste (potato peel extract) into economically valuable electrode materials. The biogenic CoFe2O4 composite showed an overpotential of 370 mV at a current density of 10 mA cm−2 and a low Tafel slope of 283 mV dec−1, whereas the ZIF@CoFe2O4 composite prepared using an in situ hydrothermal method showed an overpotential of 105 mV at 10 mA cm−2 and a low Tafel slope of 43 mV dec−1 in a 1 M KOH medium. The results demonstrated an exciting prospect of high-performance noble metal-free electrocatalysts for low-cost, high-efficiency, and sustainable hydrogen production.

Keywords

• spinel ferrite
• ZIF-8
• magnetic
• CoFe₂O₄
• oxygen evolution reaction